The fact that the Amazon rainforest produces its own weather is well known and well publicized. Some new research from the Max Planck Institute for Chemistry reveals interesting detail on how that works and how the forest is essentially a self-contained cloud-producing biogeochemcial reactor. It all comes down to miniscule organic particles in the air, produced by plants.

Submicron particles have a diameter that is smaller than a thousandth of a millimeter and serve as cloud condensation nuclei. They consist of 85 % secondary organic aerosol components. These are formed from volatile organic compounds which are released by the forest ecosystem and which can be converted to low-volatile particles through photochemical reactions and condensate. The remaining tenth of the submicron particle primarily consists of salts, minerals and soot, transported from the Atlantic and Africa by the winds.

More than 80% of supermicron particles, which have a diameter of more than a micrometer, are made up of primary biological aerosol material, such as fungal spores, pollen and plant debris, and are directly released into the air from the rainforest. They serve as ice nuclei and are very important for the evolution of precipitation.

So basically, during the rainy season, water vapor rises up from the forest, condensing on these aerosol particles. These get transported up to heights of 18 kilometers (11 miles), forming clouds, which then drop the water back to the ground (but you know how clouds work...). The plants continue to release organic matter into the atmosphere while growing, contributing again to cloud formation.

The fact that the Amazon rainforest produces its own weather is well known and well publicized. Some new research from the Max Planck Institute for Chemistry reveals interesting detail on how that works and how the